<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>TASK 13</title>
</head>
<body>

	<label>请输入北京今天空气质量：<input id="aqi-input" type="text"></label>
	<button id="button">确认填写</button>

	<div>您输入的值是：<span id="aqi-display">尚无输入</span></div>
	<script type="text/javascript">
	var input = document.getElementById('aqi-input');
	var button = document.getElementById('button');
	var display = document.getElementById('aqi-display');
	function updateValue() {
		display.innerHTML = input.value;
	}
	button.onclick = updateValue;
	</script>
</body>
</html>